customize access to your data through the use of an intuitive wizard driven interface. With Query Wizard you can quickly create and save customized queries then re-use those queries at any time. See some screen shots below to see how to use the Query Wizard. NOTE: On browse screens if you either apply or reset a query and the screen does not seem to reflect your changes, you may want to click a column header. This will resort the screen and insure the filter is applied or removed as the case may be.
Components of a Query
By definition, a query is much the same as a question. In the case of database queries, a user is asking their database a question. Computer programs use languages that we, as humans do not ordinarily use in our daily lives. In this case Query Wizard acts as our interpreter. The Query Wizard interpreter allows questions to be asked in a language that both the user and their database will understand.
Each Query may consist of one or more questions, logically connected with an AND or an OR logical operators complete a valid "computer" question Query Wizard must collect three components of information: Field, Operator and Value. Given these three components, Query Wizard will construct a meaningful question.
Field
The Field is generally representative of information contained within in the database for which the developer has made available therefore considered the subject of the question or what you would like to learn about. A few examples of fields would be Account Balance, Last Name or Zip Code.
Operator
The Operator represents the comparison to be made between the Field and Value. Due to the nature of the value, operator selections for numbers are limited when compared to those for text. For example the most common numeric operators are Greater Than, Less Than or Equal To. The nature of text operators allow for such comparisons as Contains and Begins With. The Operation Selections issues in greater detail.
Value
The Value will be compared (via the operator) to the field in your database. The value entry is the way you wish to describe the subject (field) of the question. In essence the value describes the trait the field should have (or not have). Query Wizard offers many useful features user with their value consideration.
Field Selection
This dialog is the first of three steps and is composed of a list of fields available to be queried. These fields were made available by the developer and are generally representative of information contained within in the database.
To select a field, simply highlight the desired field and press the Next button.
Operator Selection
This dialog is the second of three steps and is composed of those operators relevant to the selected field. The Operator represents the comparison to be made between the Field and Value. Due to the nature of the value, operator selections for numbers are limited when compared to those for text.
To select an operator, simply highlight the desired operator and press the Next button.
Common Operators (both numeric and text)
· Equal To
The field and the value must have the same value.
· Greater Than
The field must be greater than the value.
· Less Than
The field must be less than the value.
Text Operators
· Begins With
The field must begin with the value.
· Contains
The field must contain the value at any position within the text.
Value Entry
This dialog is the last step and is used to collect the value component of the query. This value will be compared (via the operator) to the field in your database. In essence the value describes the trait the field should have (or not have).
When the value entry has been completed simply press the Next button continue.
Case Sensitivity and Absolute Power
Query Wizard offers many useful features to assist the user with their value consideration. Two examples are Case Sensitivity and Absolute Value. Case sensitivity may be invoked if the selected field is a string while absolute values may be compared when the field is numeric.
Types of Values (constant, another field, expression)
· Constant Value
This option allows the user to type the value directly into Query Wizard. This is the default option and would normally be used with most queries.
When the field being queried is a date field the ellipses will call the built-in drop-down calendar.
· Another Field
This option is quite useful for comparing two existing database elements. This selection may be made from a list of fields identical to those in the first Query Wizard step. The actual value of this field will be used for comparison to the field selected in step one.
· Expression
This is an advanced option which requires a limited knowledge of the underlying computer language. Although more complex, when used in the appropriate context this can be a very powerful feature. This expression should return a value to be used for comparison to the field selected in step one.
Query Review
The Query Wizard review dialog allows you to review, modify or delete from the existing query. Query elements (each question) may be manipulated by first highlighting the desired element then pressing the respective button to perform the desired action.
To create a query with more than one question within the same query (compound query), simply press the AND or the OR button. This will guide the user to step one of the Query Wizard. Upon completing the three wizard steps, a new sentence will appear in the review list as illustrated above. When formulating a compound query, please ensure that you do not mix an AND with an OR. In other words use all ANDs or all ORs but never an AND and OR together in the same query. To use mixed logic such as this you will need to use the advanced Manual operation.
When the query is satisfactorily completed, press the finish button to apply the newly formulated query.
Selecting a Query
All saved queries with the same classification are displayed on this dialog in alphabetic order. To select a query simply highlight a specific description then press the button representative with the action to be performed.
Select
This button will select the highlighted query for use with the current operation.
Insert
This button will allow the creation of a new query.
Change
This button will select the highlighted query for modification. Upon completion of the modification the query may be saved with a new description (as a new copy) or you may overwrite the existing query. When the query has been successfully saved it will be applied for use in the current operation.
Delete
This button will permanently delete the currently highlighted query.
AND Join / OR Join
While only available when a query is currently active in the browse, these options will create a compound query by joining the highlighted query with the currently active query. When creating a new query the Compound Query Dialog will prompt the user for the same options.